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No. 369,666. a 2 Patented Sept. 6, 1887. Fay.;

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GARBONIZ'ING MOLD FOB ING'ANDBSCBNT ELECTRIC IGHT FILMENTS. No. 369,666. Patented ept. 6, 1887.

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@5% @Lifter-neg UNITED STATES PATENT OEEICE.

EDWARD P. THOMPSON, OF ELIZABETBQNEW JERSEY.

CARBONIZING-IVIOLD FOR INCANDESCENT-ELECTRlC-LIGHT FILAMENTS.

SPECIFICATION forming part of Letters Patent N0. 369,666, dated September 6, 1887.

Application tiled September l5, i886. Serial No. 213,573. (No model.)

To all whom it may concern:

Be it known that I, EDWARD P. THOMPSON, a citizen of the United States, residing in Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Carbonizing-Molds for Incandescent-Electric Light Filaments, of which the following is a specification.

lThe invention relates to the class of appa- Io ratus employed for carbonizing filaments for incandescent electric lights.

The object of the invention is to provide a forming and carbonizing mold which will permit a large number of filaments to be treated in a small compass, and by means of which filaments of different sizes may be simultaneously made.

The invention consists in constructing a mold rectangular in shape and grooving it in 2o one or both directions for receiving the laments. rIhe mold may be ofsquare cross section, or it may be longer in one direction than the other, accordingly as it is desired to make the filaments 'all of the same size or of two difz5 ferent sizes.

In the accompanying drawings, Figure l is a plan view of a mold embodying the features of the invention, and Fig. 2 is a cross-section of the same. Figs. 3 and 4 illustrate modifi- 3o cations.

Referring to the figures,A represents a block of carbon or other material not easily destroyed by intense heat. This block is rectanguiar in outline and it is of oval crosssection,

or of such form as to represent two filaments for incandescent electric lights when placed with ends abutting. The block is grooved in one direction, as shown at b b, and in this groove it is designed that the filament to be 4o carbonized shall loe wound. It is fastened at or near the center by ligatures b b', which are wound about the block at right angles to the direction of the tilaments. The ligatures may be of cloth, string, or other suitable material which will serve to hold the filaments in position while being carbonized. The convolutions of the lament are then cut across the centers of the block, forming two sets of loops of theproper shape. Asecond filament, d, is then wound at right angles to the rst. rIhis is bound in position by a ligature, b2 b2, and then cut, after the manner of the first. The mold is then placed in a suitable carbonizingkiln.

In Fig. 3 the mold is represented as being longer in one direction than the other,thereby rendering it possible to form lainents of two sizes upon the same mold. In Fig. 4 grooves b b and c c are represented in both directions, and this feature is applicable to the form shown in Fig. 3.

I claim as my invention- 1. A mold iorcarloonizing electric-light filaments,rectangular in shape and grooved upon its surface for receiving the iilaments,and hav- 65 ing all its edges curved to the form of the loops of the required filaments.

2. A mold for carbonizing electric-light filaments, rectangular in form and grooved in twodirections, substantially as described.

3. A mold for carbonizing electriclight filaments, groo ved in two directions for receiving the filaments, and of greater length than breadth, substantially as described.

et. The hereinbeforedescribed method of forming electric-light filaments, which consists in winding a filament upon a carbonized block, binding such filament in position by a second filament, and simultaneously carbonizing both iilaments.

In testimony whereof I have hereunto subscribed my name this 17th day of August, A.

EDVARD P. THOMPSON.

Witnesses:

DANI.. W. EDGEcoMB,

GEAELEs A. TERRY. 

